The present invention relates to a toy building set with box-shaped building elements having, in a horizontal plane defined by two directions perpendicular to each other, dimensions that are integer multiples of a first module and having, in a third direction perpendicular to this plane, a third dimension, ie the height, which is between one time and twice the first module. At least one of the building elements has a tubular opening in a first lateral face, and elements are provided that have a tenon that can be introduced into the tubular opening by a snap-effect.
Such building sets are known and marketed under the trade mark LEGO TECHNIC that pose great challenges and present many options to the user for building imaginative as well as authentic constructions. The length of the tenons is in accordance with the module of the building elements in the two directions perpendicular to each other, and interconnecting of two or more building elements by means of connecting tenons occurs only in this plane whereby building elements are interconnected side by side.
In these prior art building sets the building elements are also provided with coupling studs on one side whereas the opposite side is hollow and able to receive coupling studs on another building element. However, this possible way of interconnecting building elements is not a prerequisite for the present invention since a building system in which interconnecting occurs by means of tenons is an independent building system.
U.S. Pat. No. 2,885,822 discloses a toy construction set of hollow blocks. The walls have openings giving access to the interior of the blocks. Interconnecting clips have split opposite ends with snap beads for inserting into openings in the walls of two blocks and releasably securing the blocks adjacent each other.
EP 228 103 discloses hollow stackable building elements with coupling studs and an opposed cavity for receiving coupling studs on another element. The coupling studs have an opening for receiving a coupling pin. The coupling pling pin extends through the element and engages the coupling stud on another element.
It is desirable to have a toy building set wherein interconnecting by means of tenons with snap is also an option in the vertical direction, ie that direction where the dimension of the building elements exceeds the module in the two other directions. This is a problem, the tenons being shorter than the height of the building elements. If it was thus desired to provide these prior art building elements with tubular openings in the vertical direction (height) of the elements and with the same configuration as the horizontal openings, the vertical openings would necessarily have such length that the free ends of the tenons would not be able to enter sufficiently deeply into the openings for them to establish a snap engagement.
The present invention eliminates this problem in that the vertically extending tubular openings feature an internal flange at a distance from the ends of the openings corresponding to the first module from the first end of the tubular openings.
Hereby it is also possible to interconnect the building elements in a vertical direction by use of the same tenons as in case of side-by-side interconnecting. Thus, building elements can be interconnected horizontally as well as vertically by means of the same type of connecting bushings with tenons, and interconnecting in the vertical direction can be combined with the known interconnecting by means of studs in purely frictional engagement with the walls of a cavity. Hereby particularly strong interconnecting with increased resistance to separation is accomplished.
The toy building set according to the invention also allows the novel building elements to be interconnected with the known LEGO TECHNIC building elements in a position where they have been pivoted by 90xc2x0 whereby the coupling studs have a horizontal orientation. Now, it is possible to build horizontally with the known elements with studs in purely frictional engagement with the walls of a cavity.
Finally, two building elements according to the invention can be interconnected with their cavities facing each other and their coupling studs facing in opposite directions.